Amateur fiction is not the only situation where one will want to create some fictional pseudo-science, but ok, it's the main one. But why you would do it doesn't matter, the problem remains, some errors get done over and over, and avoiding them would save nerdier readers a lot of cringing.

1- Too much science.You're making up a world where the dead walk, identify humans, overpower and eat them. And they're also contagious. Oh, and also it's a virus, a not really alive parasite that needs to be coddled by a host cell to show any form of activity, yet it thrives in a dead host. Also it can infect a person, turn it, then have that person infect someone else in twenty minutes despite the fact that no virus can be replicated this fast simply because human cells can't work this fast. And don't forget that despite having lost the ability to produce new energy, eliminate waste or maintain tissue, the zombies survive long enough to besiege the last humans until they starve.HOW DO YOU EXPLAIN IT???The answer is you don't. Oh, there is plenty you can explain and it can be interesting, as long as you accept that there'll be holes. But if you attempt to cover every part that doesn't quite agree with reality, you'll just create more holes, lenghten your technobabble parts and eventually outright contradict science. Trust your readers' suspension of disbelief, they already expect your story to be imaginary.Image: Trying to explain away the holes in the explanation of the holes in the explanation of the holes in...... or This Is Your Brain On Technobabble.

2- Binomial nomenclatureZombies are not a species. Naming them like a species would be like naming a butterfly and its caterpillar as two different species. If scientists are going to name something, it's going to be the virus or the disease.2-a- Latin is mandatoryIf you do want to name the zombie virus, note that because viruses are only being studied and named for a relatively short time, many have non-latin names already. For the sake of example, lets say the zombie virus came from a mutated rabies virus; then Lyssavirus zombie would be a perfectly suitable binomial name. So for the love of all that is good and holy, unless you actually know Latin, do not rape Latin in vain. Don't hesitate to ask Wikipedia for the genus name of whatever virus you want your bug to be close to. Or make up your own, about anything goes - except fake Latin!

3- Super fast scienceScientists will not figure out everything about zombies, the virus or anything related in a couple of days. The smartest scientists with the fastest computers still can't provide information without the data to work with, and in the field of biology everything takes time. A virus under a microscope does nothing, figuring out how it works involves observing patients, infecting animals and cell lines, compiling stastistics on its spreading, etc. Determining how though it is involves exposing it to the usual disinfecting agents and then see if it'll still grow if introduced into a cell culture. Determining if it's sensitive to antivirals means testing in both cell lines, animals and humans, and often what works in one doesn't in the other. Every bit of a virus's behaviour depends on its host cell, and those are not always cooperating; they're needy and slow. If in your zombie infested world, you want a wealth of details to be known about the zombie virus, make the epidemic slow, or have small scale outbreaks happen a couple of years before the big one. If an african village gets destroyed, it would provide science with usable data and samples while being just one notch above conspiracy theory in the public eye.

Ok, this is all I could think of for now, other forumites are welcome to add their own pseudo-science pet-peeves and how they think it could be helped.

Make it possible for the zombie disease to spread? If zombies want to eat humans, when the horde grows large enough to eat a human before he turns after being bitten, it will stop growing. So it should be also able to spread by other means than biting, and do it easily, or you would not get more than thirty zombies or so...

Not necessarily. It wouldn't be that far fetched if the disease caused the urge to, say, chew instead of eat. That way even if there was a hoard, they wouldn't be trying to devour the person. Just kinda gnaw on them. There would still be a lot of nonviable infected but there would definitely be a much higher success rate.

Logged

Let us go singing as far as we go: the road will be less tedious. -Virgil-

Trust your readers' suspension of disbelief, they already expect your story to be imaginary.

This is a very good point and covered easily with "the characters may not know everything". It's real in the fictional world if the author puts it in. Characters can always react to the "what is" not the why. The audience may want to know why, and the author may want to convey the why, but if that's the case there should be less holes.

If for example if 1 hour after zombifying the zombies bust into flames explode the characters have to deal with that. If the author were to try to explain why that happens if could be a huge stretch (possible sure somehow, but stick with me). The point is regardless of "why", the story can remain engaging and relevant with the characters reacting to it. It is their reality even if there is no explanation.

Just like getting too technical, you probably don't want to leave the readers wondering why the hell zombies could suddenly fly and teleport without planning to give at least some sort of explanation. You could say magic, but only if it fits with the theme of the story. Otherwise, it'll just sound weird. Better to just tweak with existing theories a little than to say, "It's there 'cause it's there."

For a great example of how to fail at a new spin on zombies read Cell by Stephen King. I think I mentioned mentioned before I got the hardcover for a buck at a book sale and felt overcharged.

This applies to all fiction not just zombies so listen up. Make your characters engaging and interesting. If they are just spam the reader has no connection to you wasted your time. Some authors who are very out of touch believe characters who are very plain and boring easy to identify with (Cell) but that is because they are lazy writers who have come to look down at their audience.